(a) Field of the Invention
The present invention relates to an optical transport network, and more particularly, to a method and an apparatus for transmitting data to improve an error correction capability in the optical transport network.
(b) Description of the Related Art
In an optical transport network, forward error correcting (hereinafter, referred to as ‘TEC’) is performed in order to improve a transmission performance. ITU-T G.709 defines an optical channel transport unit (OTUk) and an optical channel data unit (ODUk) (k=1, 2, 3) in order to stably transmit a high-speed signal providing a large bandwidth in the optical transport network. One OTUk includes the ODUk corresponding to information data including an overhead and a payload (optical channel payload unit (OPUk)) and parity bytes for error correction of the ODUk.
Meanwhile, OTU1 has a bit rate of approximately 2.666 Gbit/s, OTU2 has a bit rate of approximately 10.709 Gbit/s, OTU3 has a bit rate of approximately 43.018 Gbit/s, and OTU4 has a bit rate of approximately 111.8 Gbit/s.
As such, when OTU4 transmits an optical signal of 100 Gbit/s or more, OTU4 has a transmission penalty higher than the existing OTUk (k=1, 2, 3). Therefore, definition of an error correction code having a performance higher than an error correction code of 4×256 bytes defined for error correction in the existing OTUk is required. More parity bits are required in order to improve the performance of the error correction code. Herein, when more parity bits are granted to the same information data, the bit rate further increases. That is, when the performance of the error correction code is improved as a transmission rate increases, the transmission rate further increases, thereby deteriorating the transmission performance.